1. Field of the Invention
The present invention relates to an information recording and reproducing device for recording and/or reproducing information on an information recording medium.
2. Related Art Statement
In general, an information recording medium, such as a magnetic disk is provided with sectors each having a predetermined size, for example, 512 bytes and 1024 bytes or the like and information is written on and read from a medium is executed using one of these sectors as a minimum unit.
When a plurality of various information (files) are to be recorded on the medium, there are many cases in which management information (directory) for example, the outline of the information, such as the name, recording date, and recorded location of the information is often recorded in a location different from that of information main body (data). When information is recorded in the fashion as described above, there is an advantage that desired information can be easily searched from a plurality of recorded information and the location of a vacant region can be easily specified when new information is recorded.
Since the amount of the management information is small as compared with that of the information main body, a plurality of management information is usually stored in a sector.
Further, as the memory capacity of medium is increased, a medium is divided into a plurality of partitions and handled as if there exist a plurality of mediums. For example, a medium is divided into two partitions and each partition is provided with a directory recording region and a data recording region so that the medium is handled as if there exist two mediums. With this arrangement, the medium can be used for such purposes as the quick search of target information and the secure procurement of the unused region of a specific partition by storing information a previously determined location depending upon its content.
On the other hand, a write once type information recording medium such as an optical card cannot record different information again on a sector to which information has been written once. Therefore, when management information is recorded on a sector which has the same size as that used to record data as described above, only one directory is recorded in a sector. To cope with this problem, recording sectors having a plurality of sizes are mixedly formed in the same medium and directories are recorded using sectors whose size is smaller than that of sectors used to record data.
An information recording medium such as the optical card whose standard is not widely generalized is used in various fashions depending upon users. More specifically, this means the case that computers each having a different basic design are used as devices for controlling units which read and write information from and to a medium and the case that even if the same controllers are used, they employ different operating systems. Thus, different methods of using the card are employed depending upon environments under which the card is used. That is, a problem arises in that a recording medium having recorded information by a controller or an operating system cannot be used by other controller or operating system.
Further, a problem also arises in that when the number of files to be recorded on a medium is increased, a region for recording the management information of the files is also increased accordingly and the limited recording capacity of the medium itself is consumed by the region.